Inhaler

71-75. (canceled)

An inhaler comprising a housing to receive a blister having a puncturable lid and containing a dose of medicament for inhalation by a user, a mouthpiece through which a dose of medicament is inhaled by a user, a blister piercing member comprising at least two discrete piercing heads operable to pierce a corresponding number of holes in said blister, an actuator comprising an arm pivotally mounted to the housing at one end, and an opening formed in the vicinity of each piercing head, at least one of said openings forming an airflow inlet into said blister and, at least one other of said openings forming an airflow outlet from said blister, the mouthpiece including a primary chamber having an outside air inlet in communication, via the primary chamber, with the or each airflow inlet opening and, a secondary chamber in communication with the or each airflow outlet opening such that, when a user inhales through the mouthpiece, air is drawn through the or each airflow inlet opening into the blister via the outside air inlet and the primary chamber to entrain the dose in the airflow, said entrained dose passing through the or each airflow outlet opening into the secondary chamber of the mouthpiece from where it is carried into the user's airway.